1. Field of the Invention
The present invention relates to a push button switch and, more particularly, to a push button switch in which an operating member is inserted in the axial direction to open/close a contact.
2. Description of the Related Art
Hitherto, there is a push button switch in which an operating member assembled in a housing is pushed from a side to depress a movable contact to come into contact with a fixed contact, thereby opening/closing a circuit. For example, there is a push button switch in which a tilt piece 33 having a cantilever shape is cut from a center of the flat surface of a cover member 17 constructing a housing and an operating part 34 of an operating member 16 is pressed against the tilt piece 33, thereby depressing a movable contact 14 to open a circuit (refer to Japanese Unexamined Utility Model Publication No. Hei 5-83958).
There is another push button switch having a bent portion 35 in an almost V shape whose both ends are supported in a notch 34 in a pressing plate 33 as a component of a housing. By pressing a contact pressing portion 29 of an operating member 19 against the bent portion 35, a movable contact 18 is depressed to open a circuit (refer to Japanese Unexamined Utility Model Publication No. Hei 5-1126).
In the former push button switch, however, the tilt piece 33 has a cantilever shape, so that it tends to be elastic deformed. It is not easy to accurately push the movable contact, and the operation characteristics tend to vary.
In the latter push button switch, the bent portion 35 having an almost V shape whose both ends are supported has to be deep-drawn by press work. Consequently, the process face of the bent portion 35, in particular, the tilt surface with which the contact pressing portion 29 of the operating member 19 comes into press contact tends to become rough, and the operating member 19 sliding with the tilt surface wears easily, causing a problem such that the push button switch has short life.
The present invention has been achieved in view of the problems, and an object of the invention is to provide a long-life push button switch having no variations in its operation characteristics.